Engineering Commons^™

Performance And Characterization Of A Large Format Solid State Imager, Jacob A. Mendez

Electrical and Computer Engineering ETDs

The purpose of this thesis is to validate the specifications of the CCD 486 as specified by Fairchild Imaging, the manufacturer of the CCD and Spectral Instruments, the manufacturer of the camera control electronics and supporting hardware. Specifications have been provided by both companies and are shown in Appendix A. This study is necessary because of the nature of the experiments to be analyzed using the CCD 486. In addition, the thesis will propose new testing methods for electronically shuttered CCD imagers that are not well understood.

Mimo Communication Capacity: Antenna Coupling And Precoding For Incoherent Detection, Nicolas W. Bikhazi

Theses and Dissertations

While the capacity of multiple-input multiple-output (MIMO) systems has been explored in considerable detail, virtually all literature on this topic ignores electromagnetic considerations. This dissertation explores electromagnetic effects on the capacity performance of these multi-antenna architectures. Specifically, it examines the impact of superdirectivity for compact antenna arrays, the effect of antenna mutual coupling, and MIMO performance of multi-mode optical fiber with non-linear detection. Superdirectivity can lead to abnormally large capacity bounds in a MIMO communication system, especially when the antennas are placed close together. Because superdirective behavior is difficult to achieve in practice, this work formulates an approach for limiting …

Scalable Load And Store Processing In Latency Tolerant Processors, Amit Vasant Gandhi

Dissertations and Theses

Memory latency-tolerant architectures support thousands of in-flight instructions without proportionate scaling of cycle-critical processor resources, and thousands of useful instructions can complete in parallel with a long-latency miss to memory. These architectures, however, require large queues to track all loads and stores executed while a long-latency miss is pending. Hierarchical designs alleviate cycle-time impact of these structures but the Content-Addressable-Memory (CAM) and search functions required to enforce memory ordering and provide data-forwarding place high demand on area and power.

Many recent proposals address the complexity of load and store queues. However, none of these proposals addresses the fundamental source of …

A Prototype Platform For Array Feed Development, James Richard Nagel

Theses and Dissertations

Radio frequency interference (RFI) is a growing problem for radio astronomers. One potential solution utilizes spatial filtering by placing an array of electrically small antennas at the focal plane of a parabolic reflector. This thesis documents the design and characterization of a prototype array feed and RF receiver that were used to demonstrate the spatial filtering principle. The array consists of a 7-element hexagonal arrangement of thickened dipole antennas tuned to a center frequency of 1600 MHz. The receiver is a two-stage, low-noise frequency mixer that is tunable over the entire L-band. This thesis also documents a new receiver design …

Fabrication Of Hollow Optical Waveguides On Planar Substrates, John P. Barber

Theses and Dissertations

This dissertation presents the fabrication of hollow optical waveguides integrated on planar substrates. Similar in principle to Bragg waveguides and other photonic crystal waveguides, the antiresonant reflecting optical waveguide (ARROW) is used to guide light in hollow cores filled with liquids or gases. Waveguides with liquid or gas cores are an important new building block for integrated optical sensors. The fabrication method developed for hollow ARROW waveguides makes use of standard microfabrication processes and materials. Dielectric layers are deposited on a silicon wafer using plasma-enhanced chemical vapor deposition (PECVD) to form the bottom layers of the ARROW waveguide. A sacrificial …

Design And Realization Of A Single Stage Sigma-Delta Adc With Low Oversampling Ratio, Yongjie Cheng

Theses and Dissertations

Due to the rapid growth of the communication market, a large amount of research is in process toward a high speed and high resolution sigma-delta A/D converter. This dissertation focuses on the design of a single-stage sigma-delta A/D converter with very low oversampling ratio for the wireless application. An architecture for a multibit single-stage delta-sigma A/D converter with two-step quantization is proposed. Both the MSB and LSB signals produced by the two-step quantization are fed back simultaneously to all integrator stages, making it suitable for low oversampling ratios. The two-step ADC avoids the problem that the complexity of an internal …

Obstacle Avoidance For Small Unmanned Air Vehicles, Brandon R. Call

Theses and Dissertations

Small UAVs are used for low altitude surveillance flights where unknown obstacles can be encountered. These UAVs can be given the capability to navigate in uncertain environments if obstacles are identified. This research presents an obstacle avoidance system for small UAVs. First, a mission waypoint path is created that avoids all known obstacles using a genetic algorithm. Then, while the UAV is in flight, obstacles are detected using a forward looking, onboard camera. Image features are found using the Harris Corner Detector and tracked through multiple video frames which provides three dimensional localization of the features. A sparse three dimensional …

Lightweight In-Plane Actuated Deformable Mirrors For Space Telescopes, Michael J. Shepherd

Theses and Dissertations

This research focused on lightweight, in-plane actuated, deformable mirrors, with the ultimate goal of developing a 20- meter light gathering aperture for space telescopes. The 0.127 meter diameter deformable mirror small scale testbed was modelled infinite elements using MSC.Nastran software and then used as a basis for a quasi-static controller. Experimental tracking of Zernike tip, tilt, and defocus modes was accomplished. The analytical solutions to plate-membrane and beam-string ordinary differential equations were developed. A simplified approach to modelling the axisymmetric cases was also presented. A novel static control strategy, the Modal Transformation Method, was developed to form Zernike surfaces within …

Dual Fine Tracking Control Of A Satellite Laser Communication Uplink, Louis A. Noble

Theses and Dissertations

A dual fine tracking control system (FTCS) is developed for a single aperture optical communication receiver to compensate for high frequency disturbances affecting tracking of two incident laser communication beams. The optical communication receiver resides within a payload module aboard a geosynchronous satellite, while each laser communication transmitter is housed within a module aboard a high altitude unmanned aerial vehicle (UAV). In addition to platform specific disturbances, the impact of atmospheric optical disturbances affecting tracking error are investigated. The system dynamics and FTCS are modeled and evaluated in MATLAB and SIMULINK. An optimal controller is developed to mitigate these disturbances …

A General Framework For Analyzing, Characterizing, And Implementing Spectrally Modulated, Spectrally Encoded Signals, Marcus L. Roberts

Theses and Dissertations

Fourth generation (4G) communications will support many capabilities while providing universal, high speed access. One potential enabler for these capabilities is software defined radio (SDR). When controlled by cognitive radio (CR) principles, the required waveform diversity is achieved via a synergistic union called CR-based SDR. Research is rapidly progressing in SDR hardware and software venues, but current CR-based SDR research lacks the theoretical foundation and analytic framework to permit efficient implementation. This limitation is addressed here by introducing a general framework for analyzing, characterizing, and implementing spectrally modulated, spectrally encoded (SMSE) signals within CR-based SDR architectures. Given orthogonal frequency division …

Fusion Of Imaging And Inertial Sensors For Navigation, Michael J. Veth

Theses and Dissertations

The motivation of this research is to address the limitations of satellite-based navigation by fusing imaging and inertial systems. The research begins by rigorously describing the imaging and navigation problem and developing practical models of the sensors, then presenting a transformation technique to detect features within an image. Given a set of features, a statistical feature projection technique is developed which utilizes inertial measurements to predict vectors in the feature space between images. This coupling of the imaging and inertial sensors at a deep level is then used to aid the statistical feature matching function. The feature matches and inertial …

Navigation Using Signals Of Opportunity In The Am Transmission Band, Jonathan A. Mcellroy

Theses and Dissertations

Maintaining a precision navigation solution both in a GPS hostile jamming environment and also in a GPS non-compatible terrain area is of great importance. To that end, this thesis evaluates the ability to navigate using signals from the AM band of the electromagnetic spectrum (520 to 1710 kHz). Navigation position estimates are done using multi-lateration techniques similar to GPS. However, pseudoranges are created using Time Difference of Arrival (TDOA) distances between a reference receiver and a mobile receiver, allowing the mobile receiver to obtain absolute position estimates over time. Four methods were developed for estimating the cross-correlation peak within a …

Fast Scene Based Nonuniformity Correction With Minimal Temporal Latency, Christopher A. Rice

Theses and Dissertations

The focus of this research was to derive a new algorithm for correction of gain nonuniformities in LIDAR focal plane arrays using as few frames as possible. Because of the current low production rate of LIDAR focal plane arrays there is a natural tendency for extreme nonuniformities to exist on a pixel by pixel basis as the manufacturing technique has not yet been perfected. Generally, nonuniformity correction techniques require a large number of frames and/or have obscure requirements on the translational shifts in the input image frames. This thesis presents a solution for finding multiplicative nonuniformities that exist in a …

Laser Covariance Vibrometry For Unsymmetrical Mode Detection, Michael C. Kobold

Theses and Dissertations

Simulated cross - spectral covariance (CSC) from optical return from simulated surface vibration indicates CW phase modulation may be an appropriate phenomenology for adequate classification of vehicles by structural mode. The nonlinear structural to optical relationship is close to unity, avoiding nulls and high values; optical return contains sufficient spectral ID information necessary for data clustering. The FE model has contact between the homogeneous rolled armor and vehicle hull, a simple multi - layer skin model typical of most vehicles. Most of the high frequency energy moved to lower frequencies. This nonlinearity segments contact vibration modes into two classes: symmetrical …

Unified Architecture Of Mobile Ad Hoc Network Security (Mans) System, Li Ling

Dissertations

In this dissertation, a unified architecture of Mobile Ad-hoc Network Security (MANS) system is proposed, under which IDS agent, authentication, recovery policy and other policies can be defined formally and explicitly, and are enforced by a uniform architecture. A new authentication model for high-value transactions in cluster-based MANET is also designed in MANS system. This model is motivated by previous works but try to use their beauties and avoid their shortcomings, by using threshold sharing of the certificate signing key within each cluster to distribute the certificate services, and using certificate chain and certificate repository to achieve better scalability, less …

Automatic Modulation Classification Of Communication Signals, Zaihe Yu

Dissertations

The automatic modulation recognition (AMR) plays an important role in various civilian and military applications. Most of the existing AMR algorithms assume that the input signal is only of analog modulation or is only of digital modulation. In blind environments, however, it is impossible to know in advance if the received communication signal is analogue modulated or digitally modulated. Furthermore, it is noted that the applications of the currently existing AMR algorithms designed for handling both analog and digital communication signals are rather restricted in practice. Motivated by this, an AMR algorithm that is able to discriminate between analog communication …

Fabrication And Characterization Of Back Illuminated Cmos Photodiode Array, Amitra Banerjee

Theses

With the rapid development in low-cost CMOS technology, silicon photodiodes are currently recognized as promising choice for the imager core. In this research, the arrays of back illuminated photodiodes were designed, fabricated and demonstrated with CMOS imager fabrication process on silicon wafers. The main purpose of this work was to improve the contribution of these arrays on the imaging systems before committing their design on the chips.

In this CMOS process, first the n-well, p-well, n+and p+ regions were simulated and fabricated by several implantation processes. The n-well region was implanted by phosphorus at an energy of 170 keV and …

Adaptive Control Of Micro Air Vehicles, Joshua Stephen Matthews

Theses and Dissertations

Although PID controllers work well on Miniature Air Vehicles (MAVs), they require tuning for each MAV. Also, they quickly lose performance in the presence of actuator failures or changes in the MAV dynamics. Adaptive control algorithms that self tune to each MAV and compensate for changes in the MAV during flight are explored. However, because the autopilots on MAVs are small, many of the adaptive control algorithms like those that employ least squares estimation may take too much code space, memory, and/or computing power. In this thesis we develop several Lyapunov-based model reference adaptive control (MRAC) schemes that are both …

Temperature Dependent Analytical Modeling, Simulation And Characterizations Of Hemts In Gallium Nitride Process, Hasina F. Huq

Doctoral Dissertations

Research is being conducted for a high-performance building block for high frequency and high temperature applications that combine lower costs with improved performance and manufacturability. Researchers have focused their attention on new semiconductor materials for use in device technology to address system improvements. Of the contenders, silicon carbide (SiC), gallium nitride (GaN), and diamond are emerging as the front-runners.

GaN-based electronic devices, AlGaN/GaN heterojunction field effect transistors (HFETs), are the leading candidates for achieving ultra-high frequency and high-power amplifiers. Recent advances in device and amplifier performance support this claim. GaN is comparable to the other prominent material options for high-performance …

Automated Design Space Exploration For Digital Hardware, Jonathan Logan Turnmire

Masters Theses

Hardware design in VHDL can be a tedious and daunting task. One of the final steps is to realize the design in hardware. Whether targeting a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC), some time needs to be spent optimizing the design to meet project requirements. This paper details the use of the Synplicity physical synthesis toolsets for FPGAs on the UT Solaris workstation cluster, evaluation of the Synplicity physical synthesis toolsets to determine their efficacy in achieving multiple solutions over the power-delay-area design space and evaluation of the Liberator toolset for ASIC design to …

Simulation Of Power System Response To Reactive Power Compensation, Pierre Alexander Boheme

Masters Theses

The demand of power in theUnited Stateshas doubled in the last decade. The constant increase in power flow has saturated the existing infrastructure. Modern advances in technology are changing the way utility industry increases the transmission of power throughout the country. Distributed Energy Resources are constantly improving their reliability and power capabilities.

This thesis will simulate the response of the power system to reactive power injection. The testing will take place in the Reactive Power Laboratory at Oak Ridge National Laboratory. The facility is an initiative by the U.S. Department of Energy to facilitate the development of new resource technologies. …

A Low Noise Cmos Charge-Sensitive Preamplifier With Pole/Zero Compensation For A Neutron Detection System, Steven Curtis Bunch

Masters Theses

This thesis presents the design and implementation of a low noise CMOS charge sensitive preamplifier with pole/zero compensation for a neutron detector to be installed on the Spallation Neutron Source in Oak Ridge, TN. The first prototype chip has been fabricated using Taiwan Semiconductor Manufacturing Company (TSMC) 0.35 µm process. The system contains a preamplifier, an active resistive feedback network, a pole/zero compensation network, and the first real pole input to the shaper system. Experimental results of the system show that proper functionality was achieved. The preamplifier is noise dominant with only 540 rms electron noise at 5 pF detector …

System-On-Chip Design And Test With Embedded Debug Capabilities, Tushti Marwah

Masters Theses

In this project, I started with a System-on-Chip platform with embedded test structures. The baseline platform consisted of a Leon2 CPU, AMBA on-chip bus, and an Advanced Encryption Standard decryption module. The basic objective of this thesis was to use the embedded reconfigurable logic blocks for post-silicon debug and verification.

The System-on-Chip platform was designed at the register transistor level and implemented in a 180-nm IBM process. Test logic instrumentation was done with DAFCA (Design Automation for Flexible Chip Architecture) Inc. pre-silicon tools. The design was then synthesized using the Synopsys Design Compiler and placed and routed using Cadence SOC …

Thermoelectrics For Cooling Power Electronics, Michael Ralf Starke

Masters Theses

To increase the efficiency and reduce emissions, the hybrid electric vehicle (HEV), fuel cell vehicle (FCV), and electric vehicle (EV) types were developed. All these vehicle types rely on power electronics (PEs) to function. Yet, the reliability and performance of PEs are directly related to the operating temperature. Therefore, cooling is considered an option to reduce the operating temperature.

An examination of multiple cooling methods including conventional cooling, direct and indirect cooling, and spray cooling shows that the use of thermoelectric (TE) modules has multiple justifications including reliability, thermal control, operation in harsh conditions, and the non-application of refrigerants. Nevertheless, …

A Class-E Inductive Powering Link With Backward Data Communications For Implantable Sensor Systems, Mohammad Ahsanul Adeeb

Masters Theses

The design and implementation of a wireless power and data transfer system based on inductive coupling, having the potential to be used in numerous implantable bio-medical sensors and systems, is presented. The system consists of an external (primary) unit and an internal (secondary) unit. The external unit incorporates a high-efficiency switch-mode Class-E amplifier operating at ~200 kHz for driving the primary coil. The secondary unit consists of a parallel resonant coil followed by the power recovery circuitry. Means for backward data communication from the internal to the external unit over the same pair of coils has been realized using a …

Migration From Teleoperation To Autonomy Via Modular Sensor And Mobility Bricks, Roselyne Dalanda Barreto

Masters Theses

In this thesis, the teleoperated communications of a Remotec ANDROS robot have been reverse engineered. This research has used the information acquired through the reverse engineering process to enhance the teleoperation and add intelligence to the initially automated robot. The main contribution of this thesis is the implementation of the mobility brick paradigm, which enables autonomous operations, using the commercial teleoperated ANDROS platform. The brick paradigm is a generalized architecture for a modular approach to robotics. This architecture and the contribution of this thesis are a paradigm shift from the proprietary commercial models that exist today. The modular system of …

Optimization Of The Mod-Viii One Atmosphere Uniform Glow Discharge Plasma Reactor® For Surface Energy Treatment, Truman Andrew Bonds

Masters Theses

A plasma reactor system has been developed to provide roll-to-roll surface treatment of fabrics and films using an air plasma. Effects of air plasma surface treatment at one atmosphere can include etching, cleaning, sterilization, disinfection, and increasing surface energy, all without the use of chemical inputs and with minimal toxic by-products. Webs can be continuously and uniformly treated by proper control of gas flow, electrode configuration, plasma parameters, fabric speed, and fabric tension. Tests conducted in this work focused on raising the surface energy of PET and HDPE using various electrode configurations. For industrial applications, the exposure time required to …

Vector Control And Experimental Evaluation Of Permanent Magnet Synchronous Motors For Hevs, Timothy Adam Burress

Masters Theses

The 2004 Toyota Prius exceeded sales expectations and led the automotive industry to realize that there is a healthy market for hybrid electric vehicles (HEVs). The Prius uses two interior permanent magnet motors to manipulate power flow throughout the drive system. Permanent magnet synchronous motors (PMSMs) are most suitable for HEVs and full electric vehicles due to their high efficiency, high power density, and fast dynamic response. This thesis will present vector control theory for PMSMs, with focus on interior permanent magnet motors.

The primary 50kW drive motor and inverter of the 2004 Toyota Prius Synergy drive system was removed …

Design Of An Active Stereo Vision 3d Scene Reconstruction System Based On The Linear Position Sensor Module, Julie Anne Morris

Masters Theses

Active vision systems and passive vision systems currently exist for three-dimensional (3D) scene reconstruction. Active systems use a laser that interacts with the scene. Passive systems implement stereo vision, using two cameras and geometry to reconstruct the scene. Each type of system has advantages and disadvantages in resolution, speed, and scene depth. It may be possible to combine the advantages of both systems as well as new hardware technologies such as position sensitive devices (PSDs) and field programmable gate arrays (FPGAs) to create a real-time, mid-range 3D scene reconstruction system.

Active systems usually reconstruct long-range scenes so that a measurable …

Video Stabilization And Target Localization Using Feature Tracking With Video From Small Uavs, David Linn Johansen

Theses and Dissertations

Unmanned Aerial Vehicles (UAVs) equipped with lightweight, inexpensive cameras have grown in popularity by enabling new uses of UAV technology. However, the video retrieved from small UAVs is often unwatchable due to high frequency jitter. Beginning with an investigation of previous stabilization work, this thesis discusses the challenges of stabilizing UAV based video. It then presents a software based computer vision framework and discusses its use to develop a real-time stabilization solution. A novel approach of estimating intended video motion is then presented. Next, the thesis proceeds to extend previous target localization work by allowing the operator to easily identify …